Schottky diodes typically have a metal-semiconductor junction rather than a semiconductor-semiconductor junction. They typically have a low forward voltage drop. These diodes may consist of organic materials. Organic Schottky diodes may have an organic semiconductor layer sandwiched between a single or multi-layered stack of injecting contact (IC) and a blocking contact (BC), designated IC/OSL/BC. An example of such a diode is shown in FIG. 1. FIG. 1 shows a prior art embodiment of an organic Schottky diode 10. The diode has an injecting contact 14 on a substrate 12. The organic semiconductor layer 16 resides on the injecting contact layer. The blocking contact 18 resides on the organic semiconductor layer. Materials for the organic semiconductor layer include both p-type and n-type organic semiconducting polymeric or molecular materials and the IC and BC can each consist of at least a conductive layer such as indium-tin-oxide (ITO), gold, silver, copper, aluminum, nickel, and palladium.
Solution processing techniques, such a printing, spin coating, etc., work well with organic polymer Schottky diode processes. Because of this, these have become prevalent, including those based on pi conjugated polymers such as poly(phenylene vinylenes) (PPVs) and poly(thiophenes) such as ITO/PPV/Al, ITO/PEDOT-PSS/MEH-PPV/Au, ITO/MEH-PPV:C60/Ca, ITO/P3HT/Au and the like. Recently poly(triarylamine) (PTAA) and its derivatives have become one of the most popular semiconducting polymer classes, because of their ease of processing, stability and outstanding charge transport properties.